A lot of things can drain away the capacity of that pipe that connects your computer to the Internet. It could be other people or devices on your network, or it could even be malicious applications or services running on the PC itself. The problem can get so bad that some people will toss out their computer and buy a new one.

It doesn’t have to be that way. While the problem could be coming from anywhere, it isn’t impossible to troubleshoot if you know where to look, what tools to use, and what to do when you find the culprit. In this article, I’m going to give you a hand and walk you through the process of tracking down that bandwidth hog and shutting him down.

Track Down the Bandwidth Bandit via Your Router

You could start just about anywhere when it comes to isolating the bandwidth hog on your network or inside your computer, but in order to grab at the low-hanging fruit, it’s best to start with your networkThe Best Routers and Modems for Every BudgetThe Best Routers and Modems for Every BudgetWe've rounded up the best routers and modems for every budget, including tips on what to look for when shopping for routers and modems.Read More. A few of the solutions below can focus in on a culprit quickly and resolve your problems immediately. So why waste time troubleshooting your own computer before canceling out the external issues as a possibility?

The first and quickest way to check what’s connected to your Internet through your router is the DHCP Client table. Each router is a little different, so you may need to search for which menu the table comes under. For Linksys, it’s typically under the “Status” Tab, and then the “Local Network” menu item.

Next, just click the “DHCP Client Table” button, and that’ll take you to a list of all clients that are currently logged into your network. Are there any there that you don’t recognize? If so, there could potentially be a neighbor that’s drawing out much of your bandwidth.

All you have to do to put an end to it is click on the “Delete” button to the right of that client. Just be careful not to inadvertently delete one of your own clients, because to reconnect to the network with that device, you may need to re-enter your security password again. Not a big deal, just a hassle.

Capsa is really impressive, and it’s hard to believe that it’s free software. Running Capsa, you can see traffic on your network and associated data transfer rates to and from the various hosts, which you can find under the “Protocol” tab once you press “Start” on the main welcome screen.

This is even better organized on the IP Endpoint tab, which lines up all of the hosts in one area and then in the lower pane, shows you all of the remote IP connections of the host you selected in the top pane. By the way, this is a great way to check out what your kids are up to on your network without actually installing monitoring software on their computer.

Capsa is by far my favorite. This is similar to using another bandwidth monitoring app I covered recently called NetworkMiner, except that Capsa is less about network hacking and packet sniffing, and more about monitoring your network for activities and different traffic protocols. Either application would serve you well, though.

Find Malware or Software That Is Dogging Down Your Internet

The other possibility is that it isn’t anything on your network at all that’s causing the bandwidth crunch, but instead something running right inside of your PC itself. Old computers are notorious for getting infected with little applications called “bots” that quietly run in the background, connect to some remote server, and silently send out spam emails to hundreds or thousands of email addresses a day. That’s just one example. Malicious software can consume your bandwidth in many different ways.

The way to identify those issues is by reviewing all of your network connections and identifying any that look unusual. You can do this by clicking Start -> Run and typing “CMD” and pressing Enter. When you get the command window up, type “netstat -o”.

This shows all open network connections on your computer. Depending on what you have open, this list can take a while to finish, and could scroll off the screen, so you might even append a “>>network.log” to the end of the command to log it to a text file.

Keep an eye on any strange http or IP addresses in the third column, and note the PID for those from the list. To identify that application, open up Task Manager (start->run->”TaskMgr”) and go to the services tab.

Locate the PID on the list to find the problem child. If you see any PID value that has lots of open network connections and it’s related to a service you don’t recognize or that you didn’t realize was running on your computer, stop the service and see what happens to your Internet performance. This is a good way to stumble upon a bandwidth hog with just a little bit of work.

By the way, if you didn’t know, you can also see the PID values of each process running on your computer by going into the Processes tab, clicking the “View” menu item, select columns, and check off the box for PID.

You’re bound to find the culprit between services and processes that have open network connections!

Hone in on the Culprit With the Windows Resource Monitor

In fact, while you’re in the Task Manager, to get to another bandwidth troubleshooting tool, click on the “Performance” tab, and then click on the “Resource Monitor” button at the bottom.

The resource monitor is one of the most powerful tools available in your network troubleshooting arsenal, in my opinion.

Just one quick glance at the send/receive bandwidth values under the Network panel shows me that Kaspersky is really the biggest bandwidth consumer at the moment, followed closely by Chrome. This could indicate that the antivirus software is performing a database update. What you shouldn’t see at the top of the list is some executable file that you’ve never heard of.

Once you managed to rid yourself of the nasty hijackers, you might struggle with the malware leftovers, like changed Internet or browser settings. All this can be fixed, but if you don’t ever want to go through this experience again, read up on our common sense tips to avoid catching malware in the first place.

For some reasen, Windows will not show more,
than 4 hardrives at the same time,
(something conveniently you overlooked)
take one out the othere apears,
please no patronising remarks there's
nothing wrong with the harddrive.

Same problem: External hard drive not recognized by File Explorer but visible in Disk Manager.

I solved the problem when I took ownership and assigned the right permissions (both things via File Explorer) and all the files were back! I had forgot that the drive was a NTFS file sistem and I nearly re-formatted it… Thank God I checked this option first!

interesting FYI- I accidentally hosed 2-80 gig drives on the ribbon and 1-terrabyte via the SATA card. Restored both 80m gig XP Home Edition didn't find the SATA drive(even when it was the only one connected). I took an old version of W98 SE and it formatted the drive with Fat32 and installed 98 SE which worked fine. Hooked back up the 80 gigs and used XP to format terra with NTFS and tried to install XP . Couldn't find the drive. Seems to me that I had Windows 7 on the terra before but for some reason XP won't recognize the SATA drive,. ?Maybe SATA drivers needed??What needs to be on the SATA drive for XP to recognize it?

You said "that this process will erase the files on your external drive. Copy the files off the drive to back them up first, if necessary." How can I copy the files off my drive since the reason I'm reading your article and following your instructions is precisely because I cannot have my external disk recognized and able to work? I'm confused and helpless! Please reply somebody! I need to recover my documents! Thanks.

Really really helpful - I had a 2TB external hard drive that may as well have been made out of brick as my laptop wouldn't recognize it. It just took one of the suggestions here - allocating a letter to the drive - to sort it out! Much gratitude.

Great article! I was searching for this great information! As mostly my neighbors ask me my wifi password and I cannot easily say no to them. so I applied mac filter but still I wanted to know how much of my internet they are trying to use.

From what I have seen, MacIntosh and Linux (most implementations) have utilities that perform similar tasks. The idea is to view the traffic details and become familiar with what is normal so you may recognize that which is not normal. A simple web search should bring up operating system specific instructions on what to use and how to use it.

My Cisco menu did not have anything like your example. The Capsa did not make sense to me. Even trying to type in the run command "netstat-o" just resulted in a message that it was not recognized as a command.

As the article mentioned, each router will have a different menu setup, but you should be able to locate that particular monitoring display if you search as described in the article. Also, the command is: "netstat -o". You need a space before the "-o"

If the SOFTWARE PRODUCT is marked as a free edition for the final user (FREE), it (is) provided (to) you without charge.You may not use the SOFTWARE PRODUCT in your workplace or for commercial purpose.

Good article.
You should have mentioned though that for all of these actions, you need administrator rights.
Now that's where the real problem lies when you are working on a company PC where you only have user rights.
If there are issues with the drive itself of course, you'll need other tools to recover the partitions or data on the drive.

I have used Capsa both in the free version and the full version.
Of course there are limitations in the free version. Why would anyone want to buy the full version if everything was in the free version?
It is a good program and can be helpfull in many cases.

great article, i used this method at the beginning but then, i decided to add MAC filtering to the router, its a bit of added work every time friends or family asks for wifi connectivity but the problem with neighbors is solved.

I'm interested in what surprise I have in store though - are they going to make the software stop working after 30 days? Are features going to turn off on me? Please do fill me in...because from what I can see it's pretty cool freeware, available for "non-commercial uses".

Ryan has a BSc degree in Electrical Engineering. He's worked 13 years in automation engineering, 5 years in IT, and now is an Apps Engineer. A former Managing Editor of MakeUseOf, he's spoken at national conferences on Data Visualization and has been featured on national TV and radio.